The vanity of the passing world and love are the two fundamental and heart-penetrating notes of true poetry. And they are two notes of which neither can be sounded without causing the other to vibrate. The feeling of the vanity of the passing world kindles love in us, the only thing that triumphs over the vain and transitory, the only thing that fills life again and eternalizes it.

The Tragic Sense of Life (1913) - III : The Hunger of Immortality